Touch display device and driving method thereof

ABSTRACT

A touch display device including a first substrate, a second substrate, a display medium layer, a plurality of pixel electrodes, a plurality of driving electrodes, a plurality of touch sensing electrodes, and a plurality of force-sensing electrodes is provided. The second substrate is opposite to the first substrate. The display medium layer is disposed between the first substrate and the second substrate. The pixel electrodes are disposed on the first substrate. The driving electrodes are disposed on the first substrate and overlap over the pixel electrodes. The touch sensing electrodes are disposed on one of the first substrate and the second substrate. The force-sensing electrodes are disposed on the second substrate, wherein an arrangement direction of the force-sensing electrodes is parallel to an arrangement direction of the touch sensing electrodes. A driving method of the touch display device is also provided.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims the benefit of the U.S. provisionalapplication Ser. No. 62/244,205, filed on Oct. 21, 2015, and the TWpatent application serial no. 104143712, filed on Dec. 25, 2015, all ofwhich are incorporated herein by reference in their entireties.

TECHNICAL FIELD

The present invention relates to a touch display device and drivingmethod thereof, and particularly to a touch display device capable ofsensing force-touch and driving method thereof.

BACKGROUND

Touch-sensing capacity has become necessary requirement for electronicproducts in the up-to-date consuming market. Integrating thetouch-sensing capacity with the displaying function allows theseelectronic products to perform desired functions when the users directlytouch the display screen. Such touch display devices therefore providethe users with more visual and convenient way in manipulation. However,the rapid development of application programs and rise of the wearabletouch display devices push the demand of the market to go beyond theneed for the electronic devices having only the display and touchposition-sensing functions. The touch-sensing capacity can be multiplexby having an extra function of sensing force-touch at the touch positionto accomplish more models of manipulation.

Nowadays, most of the touch display devices have force sensors attachedunder the display panel to perform the force sensing function. However,this technic easily increases the thickness of the whole touch displaydevice and the manufacturing cost, and incurs reliability issues.

SUMMARY

The present disclosure provides a touch display device to improve theabovementioned issues in thickness, manufacturing cost, and reliabilityaspects.

In accordance with an exemplary embodiment of the present disclosure, atouch display device comprises a first substrate, a second substratearranged to opposite face the first substrate, a display medium layerdisposed between the first substrate and the second substrate, aplurality of pixel electrodes disposed on the first substrate, aplurality of driving electrodes disposed on the first substrate andsuperimposed on the pixel electrodes, a plurality of touch-sensingelectrodes disposed on one of the first substrate and the secondsubstrate, and a plurality of force-sensing electrodes disposed on thesecond substrate and arranged in a direction parallel to the directionin which the touch-sensing electrodes are arranged.

In accordance with another exemplary embodiment of the presentdisclosure, a driving method of touch display device comprises thefollowing steps/methods. Providing a touch display device including afirst substrate, a second substrate, a display medium layer, a pluralityof pixel electrodes, a plurality of driving electrodes, a plurality oftouch-sensing electrodes, and a plurality of force-sensing electrodes,in which the second substrate opposite faces the first substrate, thedisplay medium layer is disposed between the first substrate and thesecond substrate, the pixel electrodes are disposed on the firstsubstrate, the driving electrodes are disposed on the first substrateand superimposed on the pixel electrodes, the touch-sensing electrodesare disposed on one of the first substrate and the second substrate, theforce-sensing electrodes are disposed on the second substrate andarranged in a direction parallel to the direction in which thetouch-sensing electrodes are arranged, and the touch display deviceincludes a display mode, a touch-sensing mode, and a force-sensing mode;and implementing one of the display mode, the touch-sensing mode, andthe force-sensing mode in a screen frame time period.

The touch display devices in accordance with various embodiments asmentioned above utilize the driving electrodes disposed on the firstsubstrate as driving electrodes in touch-sensing mode and force-sensingmode, and the touch-sensing electrodes and the force-sensing electrodesare disposed to implement touch-sensing and force-sensing. Therefore,the touch display devices in various embodiments not only sense thetouch positions but also the force-touch so as to implement variousoperations of touch-sensing. In addition, disposing at least part of thesensing electrodes including the touch-sensing electrodes and/or theforce-sensing electrodes inside the touch display devices not onlyraises the reliability of the entire device but also effectively reducesthe thickness and manufacturing cost of the touch display device.

Various other objects, advantages and features of the present inventionwill become readily apparent from the ensuing detailed description, andthe novel features will be particularly pointed out in the appendedclaims.

BRIEF DESCRIPTION OF DRAWINGS

The following detailed descriptions, given by way of example, and notintended to limit the present invention solely thereto, will be best beunderstood in conjunction with the accompanying figures:

FIG. 1A is a cross-sectional view of the touch display device inaccordance with a first exemplary embodiment of the claimed invention;

FIG. 1B to FIG. 1D are top views respectively illustrating drivingelectrodes, force-sensing electrodes, and touch-sensing electrodes ofthe FIG. 1A;

FIG. 2A is an exploded view schematically illustrating the touch displaydevice in accordance with a second exemplary embodiment of the claimedinvention;

FIG. 2B is a top view schematically illustrating force-sensingelectrode, pixel electrode, and black matrix of the FIG. 2A;

FIG. 3A is an exploded view schematically illustrating the touch displaydevice in accordance with a third exemplary embodiment of the claimedinvention;

FIG. 3B is a cross-sectional view schematically illustrating the touchdisplay device in accordance with the third exemplary embodiment of theclaimed invention;

FIG. 4 is an exploded view schematically illustrating the touch displaydevice in accordance with a fourth exemplary embodiment of the claimedinvention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

FIG. 1A to FIG. 1D respectively illustrate a touch display device andthe driving electrodes, the force-sensing electrodes, and thetouch-sensing electrodes of the touch display device in accordance witha first exemplary embodiment of the claimed invention. Referring to FIG.1A to FIG. 1D, the touch display device 100 includes a first substrate110, a second substrate 120, a display medium layer 130, a plurality ofpixel electrodes 140, a plurality of driving electrodes 150, a pluralityof touch-sensing electrodes 160, and a plurality of force-sensingelectrodes 170. The second substrate 120 and the first substrate 110 arearranged in an opposite face-to-face manner.

Specifically, the display medium layer 130 is disposed between the firstsubstrate 110 and the second substrate 120. The pixel electrodes 140 aredisposed on the first substrate 110. The driving electrodes 150 aredisposed on the first substrate 110 and overlap over the pixelelectrodes 140. The touch-sensing electrodes 160 are disposed on one ofthe first substrate 110 and the second substrate 120. The force-sensingelectrodes 170 are disposed on the second substrate 120. Theforce-sensing electrodes 170 are arranged in a direction parallel to thedirection in which the touch-sensing electrodes 160 are arranged.

Either of the first substrate 110 and the second substrate 120 may bemade of, but not limited to, glass, plastic, or composite material. Thedistance between the first substrate 110 and the second substrate 120may be changed due to the press of a user on the touch display device100, and thus results in change of the variable interval G between theforce-sensing electrodes 170 and the driving electrodes 150. In oneembodiment, a least one spacer (not shown) may be disposed between thefirst substrate 110 and the second substrate 120 to avoid excesscompression of the distance between the first substrate 110 and thesecond substrate 120. In another embodiment, a plurality of kinds ofspacers with different heights (not shown) may be disposed between thefirst substrate 110 and the second substrate 120 such that one kind ofthe spacers supports against the first substrate 110 and the secondsubstrate 120 while the other kind of the spacers supports against onlyone of the first substrate 110 and the second substrate 120, and therebyallows change of the distance between the first substrate 110 and thesecond substrate 120 when the touch display device 100 is applied withan external force.

In one embodiment, the display medium layer 130 may be made of non-solidmaterials such as liquid crystal materials, electrophoretic materials,electro-wetting materials or the combination thereof. Therefore, thevariable interval G may be changed by pressing the touch display device100. In another embodiment, the display medium layer 130 may be made ofsolid materials such as organic light-emitting material or semiconductormaterial. Furthermore, there may be a space existing between the displaymedium layer 130 and the first substrate 110 to allow change of thevariable interval G when a user press the touch display device 100. Inanother embodiment, the touch display device 100 may include a backlightmodule BL to provide light sources required for display. In this way,the first substrate 110 may be disposed between the second substrate 120and the backlight module BL. Alternatively, the backlight module BL maybe saved when the display medium layer 130 is made of self-luminousmaterial.

The pixel electrodes 140 and the driving electrodes 150 may be formed onthe first substrate 110 in sequences such that the pixel electrodes 140are disposed between the driving electrode 150 and the first substrate.The touch display device 100 may further include an insulating layerIN1. The insulating layer IN1 may be disposed between the pixelelectrodes 140 and the driving electrode 150 to electrically isolate thepixel electrodes 140 from the driving electrodes 150. In anotherembodiment, the pixel electrodes 140 and the driving electrodes 150 maybe formed on the first substrate 110 in reverse sequences such that thedriving electrodes 150 are disposed between the pixel electrodes 140 andthe first substrate 110.

The pixel electrodes 140 and the driving electrodes 150 may be usedtogether to form an electric field for driving the display medium layer130 and therefore to accomplish display function. Specifically, adisplay mode of the touch display device 100 may be performed when adisplay driving waveform is supplied to the pixel electrodes 140, and acommon voltage is supplied to the driving electrodes 150. Theforce-sensing electrodes 170 may influence the electric field fordriving the display medium layer 130 since they are disposed near thedisplay medium layer 130. To avoid this influence in the display mode,the force-sensing electrodes 170 may be supplied with a fixed voltage.The fixed voltage may be, but not limited to a common voltage or aground signal.

The driving electrodes 150 may also be used as driving electrodes in thetouch-sensing and force-sensing modes besides as the common electrodesin the display mode. In one embodiment, the size of each of the drivingelectrodes 150 may be larger than the size of each of the pixelelectrodes 140 such that the driving electrodes 150 covers a pluralityof pixel electrodes 140 and each of the driving electrodes 150 overlapsa plurality of pixel electrodes 140.

The pixel electrodes 140 and the driving electrodes 150 may be made ofelectrically conductive materials with high or enough lighttransparency. The electrically conductive materials with high lighttransparency may include but not limited to metal oxides such as indiumtin oxide, indium oxide, or tin oxide. The electrically conductivematerials with enough light transparency may include but not limited tometal mesh layers such as nano-silver wires.

The touch-sensing electrodes 160 and the force-sensing electrodes 170may be formed on the second substrate 120 in sequences. In oneembodiment, the touch-sensing electrodes 160 and the force-sensingelectrodes 170 are disposed between the second substrate 120 and thedisplay medium layer 130, and the force-sensing electrodes 170 aredisposed between the touch-sensing electrodes 160 and the drivingelectrodes 150. The touch display device 100 may further include aninsulating layer IN2. The insulating layer IN2 may be disposed betweenthe touch-sensing electrodes 160 and the force-sensing electrodes 170 toelectrically isolate the touch-sensing electrodes 160 from theforce-sensing electrodes 170. In another embodiment, the touch-sensingelectrodes 160 and the force-sensing electrodes 170 may be disposed ontwo opposite surfaces of the second substrate 120, respectively. For anexample, the touch-sensing electrodes 160 may be disposed on an outersurface of the second substrate 120, i.e. the surface distant from thedisplay medium layer 130, while the force-sensing electrodes 170 may bedisposed on an inner surface of the second substrate 120. i.e. thesurface adjacent to the display medium layer 130, as shown in FIG. 3A.In this case, the insulating layer IN2 may be saved.

The driving electrodes 150 and the touch-sensing electrodes 160 arearranged in a cross manner, and the driving electrodes 150 and theforce-sensing electrodes 170 are arranged in a cross manner. Forexample, the driving electrodes 150 may be disposed along a firstdirection D1 while each of the driving electrodes 150 extends along asecond direction D2 different from the first direction D1. Theforce-sensing electrodes 170 may be disposed along the second directionD2 while each of the force-sensing electrodes 170 extends along thefirst direction D1. The touch-sensing electrodes 160 may be disposedalong the second direction D2 while each of the touch-sensing electrodes160 extends along the first direction D1. The first direction D1 and thesecond direction D2 are crossed and may be perpendicular to each otherin one embodiment.

The touch-sensing electrodes 160 and the force-sensing electrodes 170may be made of electrically conductive materials with high or enoughlight transparency. The electrically conductive materials with highlight transparency may include but not limited to metal oxides such asindium tin oxide, indium oxide, or tin oxide. The electricallyconductive materials with enough light transparency may include but notlimited to metal mesh layers such as nano-silver wires.

The driving electrodes 150 and the touch-sensing electrodes 160 may beused together in a touch-sensing mode of the touch display device 100.In the touch-sensing mode, the driving electrodes 150 may be suppliedwith touch driving waveforms and read the touch-sensing signals fromeach of the touch-sensing electrodes 160. When a user finger or a touchmedium such as a touch pen press the touch screen of the touch displaydevice 100, the electric field between the driving electrodes 150 andthe touch-sensing electrodes 160 changes and produces a correspondingtouch-sensing signal. In this way, the touch position of the touchmedium can be obtained by detecting the position where the touch-sensingsignals change.

In manipulation of the touch-sensing mode, the pixel electrodes 140 maybe floating and the force-sensing electrodes 170 may be supplied with afixed voltage. Therefore, the state of the display medium layer 130would not be easily changed in the manipulation of the touch-sensingmode, and which helps to keep the display quality normal. The fixedvoltage may be a common voltage or a ground signal. In anotherembodiment, the force-sensing electrode 170 may be floating.

The driving electrodes 150 and the force-sensing electrodes 170 may beused together in a force-sensing mode of the touch display device 100.In the force-sensing mode, the driving electrodes 150 may be suppliedwith touch driving waveforms and read the force-sensing signals fromeach of the force-sensing electrodes 170. When a user press the touchdisplay device 100, the capacitance change between the force-sensingelectrodes 170 and the driving electrodes 150 can be used to measure thevariation of the variable interval G and to calculate magnitude of theapplied force.

In manipulation of the force-sensing mode, the pixel electrodes 140 maybe floating. In this way, the state of the display medium layer 130would not be easily changed in the manipulation of the force-sensingmode, and which helps to keep the display quality normal. Besides, inthe force-sensing mode, the touch-sensing electrodes 160 may be suppliedwith a fixed voltage. The fixed voltage may be a common voltage or aground signal. Therefore, the influence of the finger capacitance on themutual-capacitance type force detection could be shielded and theprecision of the force detection can be improved. Alternatively, thetouch-sensing electrodes 160 may be floating.

Referring to FIG. 1A, each of the force-sensing electrodes 170 may becovered by one of the touch-sensing electrodes 160, such as making thewidth W170 of each of the force-sensing electrodes 170 smaller than thewidth W160 of each of the touch-sensing electrodes 160, to avoid thatthe electric field of the touch-sensing electrodes 160 is shielded bythe force-sensing electrodes 170. In this way, the fringe field effectcan be used to implement touch detection in the touch display device100. In this embodiment, although the force-sensing electrodes 170 andthe touch sensing electrodes 160 are illustrated in a one-to-one manner,the amount of the force-sensing electrodes 170 is adjustable dependingon the actual requirement. As an example, the amount of theforce-sensing electrodes 170 may be less than the amount of thetouch-sensing electrodes 160.

The driving electrodes 150 may be served as driving electrodes in thetouch-sensing and force-sensing modes. The driving electrodes 150 andthe touch-sensing electrodes 160 may be used together to implement themutual-capacitance type touch-sensing, while the driving electrodes andthe force-sensing electrodes 170 may be used together to implement thecapacitance type force-sensing. The touch display device 100 may be usedto simultaneously sense the touch position and the force-touch andtherefore to implement various operations of touch-sensing.

Furthermore, disposing the sensing electrodes including thetouch-sensing electrodes 160 and the force-sensing electrodes 170 insidethe touch display device 100 not only improve the reliability of theentire device but also saves extra substrates and adhesive layers thatmay be required for disposing force-sensing layers. Therefore, thethickness and manufacturing cost of the touch display device 100 can beeffectively reduced.

The touch display device 100 may further include other elementsaccording to different requirements. For an example, the touch displaydevice 100 may further include a plurality of wires to connect theabovementioned electrodes to corresponding control circuits. In oneembodiment, the touch display device 100 may further include a pluralityof first wires L1, a plurality of second wires L2, a plurality of thirdwires L3, and a plurality of conductive bumps TH. Referring to FIGS. 1Bto 1D, each of the first wires L1 is connected to one of the drivingelectrodes 150, each of the second wires L2 is connected to one of thetouch-sensing electrodes 160. The third wires L3 and the first wires L1may be disposed on the insulating layer IN1, and each of theforce-sensing electrodes 170 is correspondingly connected to one of thethird wires L3 via one of the conductive bumps TH. In this way, thecontrol circuits (not shown) for the force-sensing electrodes 170 andthe control circuits (not shown) for the driving electrodes 150 can beintegrated together. In other words, an integrated control circuit isused to provide driving signals in force-sensing and touch-sensingmodes. The amount and the disposition of the conductive bumps TH, andthe wiring layout and/or the wiring width and/or the wiring density ofthe first wires L1, second wires L2, and/or third wires L3 are notlimited by the illustration of the FIGS. 1A to 1D. The first wires L1,second wires L2, third wires L3, conductive bumps TH may be made of, butnot limited to, metal to reduce resistance, or of any electricallyconductive materials.

The touch display device 100 is driven in a screen frame time period toimplement one of the display mode, the touch-sensing mode, and theforce-sensing mode. The screen frame time period may be one-sixtiethsecond. In the screen frame time period, the touch display device 100can be manipulated to implement one or two or all of the display mode,touch-sensing mode, and force-sensing mode.

In one embodiment, the display mode, the touch-sensing mode, and theforce-sensing mode may, but not limited to, be implemented separately.In this case, the force-sensing electrodes 170 may be floating orsupplied with a fixed voltage when the touch display mode is manipulatedin the touch-sensing mode, while the touch-sensing electrodes 160 may befloating electrodes or supplied with a fixed voltage when the touchdisplay mode is manipulated in the force-sensing mode.

In another embodiment, the touch-sensing mode and the force-sensing modemay be implemented simultaneously in a screen frame time period, whereinthe pixel electrodes 140 may be floating electrodes and the drivingelectrodes 150 may be supplied with touch driving waveforms and read theforce-sensing signals from each of the force-sensing electrodes 170 andread the touch-sensing signals from each of the touch-sensing electrodes160.

Referring to FIG. 2A to FIG. 4, the various touch display devices inaccordance with other embodiments of the claimed invention are shown,wherein the same elements as or similar elements to the above-mentionedelements may be indicated with same or similar reference numerals and/orsymbols and would not be described redundantly. FIG. 2A is an explodedview schematically illustrating the touch display device in accordancewith a second exemplary embodiment of the claimed invention. Althoughthe elements shown in FIG. 2A are illustrated in a stacked manner witheach being a plane, each of the elements actually has a specificthickness. FIG. 2B is a top view schematically illustratingforce-sensing electrode, pixel electrode, and black matrix of the FIG.2A.

Referring to FIGS. 2A and 2B, the touch display device 200 may furtherinclude a plurality of scanning lines SL, a plurality of data lines DL,a plurality of active elements AD, and a black matrix layer 290. Thescanning lines SL, the data lines DL, and the active elements AD aredisposed on the first substrate 110, and the scanning lines SL and thedata lines DL are electrically isolated with each other and disposed ina staggered manner to form a plurality of sub-pixel regions P. The pixelelectrodes 140 are respectively disposed in the sub-pixel regions P.Each of the active elements AD is switched on or off via control of oneof the scanning lines SL. When the active elements AS are switched on,the pixel electrodes 140 may be supplied with display driving waveformsvia one of the data lines DL.

The black matrix layer 290 is disposed between the touch-sensingelectrodes 160 and the second substrate 120 to shield those elementsthat are required to be concealed inside the touch display device 200and to simultaneously increase the contrast of the touch display device200. The black matrix layer 290 may include a plurality of shutterstrips 292. The shutter strips 292 may be disposed in correspondencewith the position of the scanning lines SL and the data lines DL and maybe intersected to form a plurality of openings O290. Each of theopenings O290 exposes partial region of each of the pixel electrodes 140and each of the openings O290 is suited to accommodate color filterpattern CF for color filtering.

In one embodiment, the force-sensing electrodes 270 may be composed ofmetal mesh electrodes. Specifically, the force-sensing electrodes 270may be composed of a plurality of metal bars 272 with each metal bar 272having a width W272 less than the width W292 of the shutter strips 292and being wholly positioned under the shutter strip 292. In this way,the black matrix layer 290 covers the force-sensing electrodes 270 andshields the metal bars 272 such that the touch display device 200 hastouch-sensing and force-sensing functions without incurring visualissues.

The metal bars 272 are disposed in a cross manner to form a plurality ofopenings O270. Each of the openings O270 exposes one of the pixelelectrodes 140. The size and amount of the openings O270 of each of theforce-sensing electrodes 270, and the wiring layout, the wiring width,and the wiring density of the force-sensing electrodes 270 may beadjusted according to resolution and capacitance requirement forforce-sensing. In addition, the width W270 of each of the force-sensingelectrodes 270 is not larger than the width W160 of each of thetouch-sensing electrodes 160 so as to avoid that the force-sensingelectrodes 270 shield the electric field of the touch-sensing electrodes160. In this way, the touch display device 200 is allowed to implementthe touch detection by using the fringe field effect.

FIG. 3A is an exploded view schematically illustrating the touch displaydevice in accordance with a third exemplary embodiment of the claimedinvention. Although the elements shown in FIG. 3A are illustrated in astacked manner with each being a plane, each of the elements actuallyhas a specific thickness. FIG. 3B is a cross-sectional viewschematically illustrating the touch display device in accordance withthe third exemplary embodiment of the claimed invention. In thisembodiment, the touch display device 300 of FIG. 3 is similar to thetouch display device 200, and the touch-sensing electrodes 160 and theforce-sensing electrodes 270 are disposed on two opposite surfaces ofthe second substrate 120 to save the insulating layer IN2.

FIG. 4 is an exploded view schematically illustrating the touch displaydevice in accordance with a fourth exemplary embodiment of the claimedinvention. Although the elements shown in FIG. 4 are illustrated in astacked manner with each being a plane, each of the elements actuallyhas a specific thickness. In this embodiment, the touch display device400 is similar to the touch display device 200, and the touch-sensingelectrodes 460 are disposed on the first substrate 110 and on the samelayer disposed with the driving electrodes 450. With this structure, thetouch display device 400 implements the display mode by supplying thepixel electrodes 140 with display driving waveforms and supplying thedriving electrodes 450 and the touch-sensing electrodes 460 with acommon voltage. In other words, the driving electrodes 450 and thetouch-sensing electrodes 460 are together served as common electrodesfor display. Additionally, in the display mode, the force-sensingelectrodes 270 may be supplied with a fixed voltage to avoid that theforce-sensing electrodes 270 influence the electric field for drivingthe display medium layer 130. The fixed voltage may include a commonvoltage or a ground signal.

The touch display device 400 may further include a plurality ofconnection lines 470. The connection lines 470 are disposed on the firstsubstrate 110 and electronically insulated from the touch-sensingelectrodes 460. In addition, each of the connection lines 470 connectstwo adjacent driving electrodes 450 in series along the direction inwhich the touch-sensing electrodes 460 are disposed. There may beinsulating layers (not shown) interposed between the connection lines470 and the driving electrodes 450 (and the touch-sensing electrodes460), and the insulating layer may be formed with a plurality ofopenings through which the connection lines connect the correspondingdriving electrode 450. In this way, the mutual-capacitance type sensingmethod is used in the touch display device 400 to implementtouch-sensing function such as sensing touch positions.

Furthermore, the vertical projections of the force-sensing electrodes270 and the driving electrodes 450 on the first substrate 110 areoverlapped with each other. In this way, the touch display device 400implements force-sensing function with the capacitance-sensing method.It is to be noted that the abovementioned display mode, thetouch-sensing mode, and the force-sensing mode may be applied to thisembodiment. For an example, in manipulation of the force-sensing mode,the driving electrodes 450 may be supplied with driving waveforms andread the force-sensing signals from the force-sensing electrodes 270.Thereby, the magnitude of the applied force can be calculated.

In sum, the driving electrodes disposed on the first substrate areserved as driving electrodes in touch-sensing mode and force-sensingmode, and the touch-sensing electrodes and the force-sensing electrodesare disposed to implement mutual-capacitance touch-sensing andmutual-capacitance force-sensing according to the touch display devicesin various embodiments. Therefore, the touch display devices in variousembodiments not only sense the touch positions but also the force-touchso as to implement various operations of touch-sensing. In addition,disposing at least part of the sensing electrodes including thetouch-sensing electrodes and/or the force-sensing electrodes inside thetouch display devices not only raises the reliability of the entiredevice but also effectively reduces the thickness and manufacturing costof the touch display device. In one embodiment, utilizing thetouch-sensing electrodes to cover the force-sensing electrodes avoidsthe situation that the electric field of the touch-sensing electrodesmay be shielded by the force-sensing electrodes disposed between thetouch-sensing electrodes and the driving electrodes, and thereby thetouch display device is allowed to simultaneously or separatelyimplement touch-sensing and force-sensing. It is understood that thetouch display device described above may be driven by self-capacitancesensing method. Specifically, the driving signals are applied to thedriving electrodes and the touch and/or force sensing signal are readfrom the driving electrodes.

Having described at least one of the embodiments of the claimedinvention with reference to the accompanying drawings, it will beapparent to those skills that the invention is not limited to thoseprecise embodiments, and that various modifications and variations canbe made in the presently disclosed system without departing from thescope or spirit of the invention. Thus, it is intended that the presentdisclosure cover modifications and variations of this disclosureprovided they come within the scope of the appended claims and theirequivalents. Specifically, one or more limitations recited throughoutthe specification can be combined in any level of details to the extentthey are described to accomplish the touch display devices.

What is claimed is:
 1. A touch display device, comprising: a firstsubstrate on which a plurality of pixel electrodes are disposed; aplurality of driving electrodes disposed on the first substrate andsuperimposed on the pixel electrodes; a second substrate arranged toopposite face the first substrate with a plurality of force-sensingelectrodes being disposed on the second substrate to face the drivingelectrodes; a display medium layer disposed between the first substrateand the second substrate; and a plurality of touch-sensing electrodesdisposed on the second substrate and arranged in a direction parallel toa direction in which the force-sensing electrodes are arranged; whereinthe driving electrodes are supplied with a common voltage to drive thedisplay medium layer in a display mode, supplied with touch drivingwaveforms for detection of touch-sensing signals produced from thetouch-sensing electrodes in a touch-sensing mode, and supplied with thetouch driving waveforms for detection of force-sensing signals producedfrom the force-sensing electrodes in a force-sensing mode, and aninterval across the display medium layer between the force-sensingelectrodes and the driving electrodes is variable, and the force-sensingelectrodes are disposed between the touch-sensing electrodes and thedriving electrodes and each of the force-sensing electrodes is coveredby one of the touch-sensing electrodes.
 2. The touch display device ofclaim 1, wherein width of each of the force-sensing electrodes issmaller than width of each of the touch-sensing electrodes.
 3. The touchdisplay device of claim 1, wherein each of the driving electrodesoverlaps the pixel electrodes.
 4. The touch display device of claim 1,wherein the force-sensing electrodes are metal mesh electrodes.
 5. Thetouch display device of claim 1, further comprising: a black matrixlayer disposed between the touch-sensing electrodes and the secondsubstrate, wherein the black matrix include a plurality of shutterstrips to cover the force-sensing electrodes.
 6. A driving method oftouch display device, comprising: providing a touch display deviceincluding a first substrate, a second substrate, a display medium layer,a plurality of pixel electrodes, a plurality of driving electrodes, aplurality of touch-sensing electrodes, and a plurality of force-sensingelectrodes; wherein the second substrate opposite faces the firstsubstrate, the display medium layer is disposed between the firstsubstrate and the second substrate, the pixel electrodes are disposed onthe first substrate, the driving electrodes are disposed on the firstsubstrate and superimposed on the pixel electrodes, the touch-sensingelectrodes are disposed on the second substrate, the force-sensingelectrodes are disposed on the second substrate and between thetouch-sensing electrodes and the driving electrodes to face the drivingelectrodes and arranged in a direction parallel to a direction in whichthe touch-sensing electrodes are arranged, the driving electrodes areused to drive the display medium layer in a display mode, and fordetection of signals produced from the touch-sensing electrodes in atouch-sensing mode, and for detection of signals produced from theforce-sensing electrodes in a force-sensing mode, an interval across thedisplay medium layer between the force-sensing electrodes and thedriving electrodes is variable and each of the force-sensing electrodesis covered by one of the touch-sensing electrodes; and implementing oneof the display mode, the touch-sensing mode, and the force-sensing modein a screen frame time period.
 7. The driving method of claim 6, whereinthe display mode, the touch-sensing mode, and the force-sensing mode areimplemented separately.
 8. The driving method of claim 6, wherein thetouch-sensing mode and the force-sensing mode are implemented separatelyin the screen frame time period.
 9. The driving method of claim 6,wherein the touch-sensing mode and the force-sensing mode areimplemented simultaneously in the screen frame time period.
 10. Thedriving method of claim 9, wherein the method of implementingsimultaneously the touch-sensing mode and the force-sensing mode in thescreen frame time period includes: floating the pixel electrodes;supplying a touch driving waveform to the driving electrodes; reading aforce-sensing signal from each of the force-sensing electrodes; andreading a touch-sensing signal from each of the touch-sensingelectrodes.
 11. The driving method of claim 6, wherein the method ofimplementing the display mode includes: providing a display drivingwaveform to the pixel electrodes; and supplying a common voltage to thedriving electrodes.
 12. The driving method of claim 11, wherein themethod of implementing the display mode further includes: supplying afixed voltage to the force-sensing electrodes.
 13. The driving method ofclaim 6, wherein the method of implementing the touch-sensing modeincludes: floating the pixel electrodes; supplying a touch drivingwaveform to the driving electrodes; supplying a fixed voltage to theforce-sensing electrodes or floating the force-sensing electrodes; andreading a touch-sensing signal from each of the touch-sensingelectrodes.
 14. The driving method of claim 6, wherein the method ofimplementing the force-sensing mode includes: floating the pixelelectrodes; supplying a touch driving waveform to the drivingelectrodes; supplying a fixed voltage to the touch-sensing electrodes orfloating the touch-sensing electrodes; and reading a force-sensingsignal from each of the force-sensing electrodes.
 15. The driving methodof claim 6, wherein the method of implementing the display modeincludes: providing a display driving waveform to the pixel electrodes;and supplying a common voltage to the driving electrodes and thetouch-sensing electrodes.